Is this correct?

[Bio-RadAbs]

I noticed Moz using the following for its homepage

Is this best practice though?  The reason I ask is that, I use  and I've been reading this page by Google

http://googlewebmastercentral.blogspot.co.uk/2013/04/5-common-mistakes-with-relcanonical.html

5 common mistakes with rel=canonical

Mistake 2: Absolute URLs mistakenly written as relative URLs

The tag, like many HTML tags, accepts both relative and absolute URLs. Relative URLs include a path “relative” to the current page. For example, “images/cupcake.png” means “from the current directory go to the “images” subdirectory, then to cupcake.png.” Absolute URLs specify the full path—including the scheme like http://.

Specifying (a relative URL since there’s no “http://”) implies that the desired canonical URL is http://example.com/example.com/cupcake.html even though that is almost certainly not what was intended. In these cases, our algorithms may ignore the specified rel=canonical. Ultimately this means that whatever you had hoped to accomplish with this rel=canonical will not come to fruition.

[Bio-RadAbs]

Thanks

[ATP]

Ow im sorry, totally mis understood - sorry if i was explaining something you understood.

Moz use

you said they use

/> i presume now you mean the / at the end of the tag.

This is an old school closing tag. HTML elements were traditionally opened and closed in HTML versions before HTML5. Normally this is done obviously with tags such the opener "

" and closer  "

". However some elements dont have a seperate closing tag such as "" tags. In older html versions these were closed using the format

Missing these tags didn't used to do much as most browsers rendered the page correctly anyways, but best practice was to include the / to close elements. However with the dawn of HTML5 things changed.

HTML5 doesn't require the closing tag. Elements that used to require one now simply dont. Browsers still understand both versions absolutely fine and its kinda ok to use either. But the most modern and correct practice is to use it without.

Edit:

Racking my brain, i believe the / was added as best practice to assure compatibility with XHTML which was pegged to be the next version of HTML. When XHTML was scrapped in favour of HTML5 it changed. Somebody may correct me on this one though

[Bio-RadAbs]

Thanks, I realise the usage should be a correct relative URL or a correctly formed absolute URL. In Moz's case, they used a correctly formed absolute URL.

My question is more around...why not use "/"?

Cyto

[ATP]

Looks fine to me, i think you misunderstand Mistake 2

They are using an absolute URL

If they did the "mistake 2" their canonical tag would look like

---

You canonical tags should always be absolute for good practice

is correct

or any variant of this would be wrong